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1.
J Biol Chem ; 300(9): 107728, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39214298

RESUMO

Leber's Hereditary Optic Neuropathy (LHON) is a rare, maternally inherited eye disease, predominantly due to the degeneration of retinal ganglion cells (RGCs). It is associated with a mitochondrial DNA (mtDNA) point mutation. Our previous study identified that the m.15927G > A homoplasmic mutation damaged the highly conserved base pairing (28C-42G) in anticodon stem of tRNAThr, caused deficient t6A modification and significantly decreased efficiency in aminoacylation and steady-state levels of tRNAThr, and led to mitochondrial dysfunction. Meanwhile, mechanisms underlying mtDNA mutations regulate intracellular signaling related to mitochondrial and cellular integrity are less explored. Here, we manifested that defective nucleotide modification induced by the m.15927G > A mutation interfered with the expression of nuclear genes involved in cytoplasmic proteins essential for oxidative phosphorylation system (OXPHOS), thereby impacting the assemble and integrity of OXPHOS complexes. As a result of these mitochondrial dysfunctions, there was an imbalance in mitochondrial dynamics, particularly distinguished by an increased occurrence of mitochondrial fission. Excessive fission compromised the autophagy process, including the initiation phase, formation, and maturation of autophagosomes. Both Parkin-mediated mitophagy and receptor-dependent mitophagy were significantly impaired in cybrids haboring the m.15927G > A mutation. These changes facilitated intrinsic apoptosis, as indicated by increased cytochrome c release and elevated levels of apoptosis-associated proteins (e.g., BAK, BAX, cleaved caspase 9, cleaved caspase 3, and cleaved PARP) in the mutant cybrids. This study demonstrates that the m.15927G > A mutation contributes to LHON by dysregulating OXPHOS biogenesis, aberrant quality control, increased autophagy, inhibited mitophagy, and abnormal apoptosis.

2.
Gene ; 930: 148853, 2024 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-39147111

RESUMO

Leber's hereditary optic neuropathy (LHON) is a maternal inherited disorder, primarily due to mitochondrial DNA (mtDNA) mutations. This investigation aimed to assess the pathogenicity of m.3635G>A alteration known to confer susceptibility to LHON. The disruption of electrostatic interactions among S110 of the MT-ND1 and the side chain of E4, along with the carbonyl backbone of M1 in the NDUFA1, was observed in complex I of cybrids with m.3635G>A. This disturbance affected the complex I assembly activity by changing the mitochondrial respiratory chain composition and function. In addition, the affected cybrids exhibited notable deficiencies in complex I activities, including impaired mitochondrial respiration and depolarization of its membrane potential. Apoptosis was also stimulated in the mutant group, as witnessed by the secretion of cytochrome c and activation of PARP, caspase 3, 7, and 9 compared to the control. Furthermore, the mutant group exhibited decreased levels of autophagy protein light chain 3, accumulation of autophagic substrate P62, and impaired PINK1/Parkin-dependent mitophagy. Overall, the current study has confirmed the crucial involvement of the alteration of the m.3635G>A gene in the development of LHON. These findings contribute to a deeper comprehension of the pathophysiological mechanisms underlying LHON, providing a fundamental basis for further research.


Assuntos
Apoptose , Mitocôndrias , Mitofagia , NADH Desidrogenase , Atrofia Óptica Hereditária de Leber , Atrofia Óptica Hereditária de Leber/genética , Atrofia Óptica Hereditária de Leber/metabolismo , Atrofia Óptica Hereditária de Leber/patologia , Humanos , Mitofagia/genética , Apoptose/genética , Mitocôndrias/metabolismo , Mitocôndrias/genética , Mitocôndrias/patologia , NADH Desidrogenase/genética , NADH Desidrogenase/metabolismo , Mutação , DNA Mitocondrial/genética , Potencial da Membrana Mitocondrial/genética , Proteínas Quinases
3.
J Control Release ; 373: 410-425, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39038545

RESUMO

Dry powder inhalers (DPIs) are widely employed to treat respiratory diseases, offering numerous advantages such as high dose capacity and stable formulations. However, they usually face challenges in achieving sufficient pulmonary drug delivery and minimizing excessive oropharyngeal deposition. This review provides a new viewpoint to address these challenges by focusing on the role of swirling flow, a crucial yet under-researched aspect that induces strong turbulence. In the review, we comprehensively discuss both key classic designs (tangential inlet, swirling chamber, grid mesh, and mouthpiece) and innovative designs in inhalers, exploring how the induced swirling flow initiates powder dispersion and promotes delivery efficiency. Valuable design considerations to effectively coordinate inhalers with formulations and patients are also provided. It is highlighted that the delicate manipulation of swirling flow is essential to maximize benefits. By emphasizing the role of swirling flow and its potential application, this review offers promising insights for advancing DPI technology and optimizing therapeutic outcomes in inhaled therapy.


Assuntos
Sistemas de Liberação de Medicamentos , Inaladores de Pó Seco , Desenho de Equipamento , Humanos , Administração por Inalação , Pulmão/metabolismo , Animais
4.
Commun Med (Lond) ; 4(1): 31, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418628

RESUMO

BACKGROUND: Long-term monitoring of Electrocardiogram (ECG) recordings is crucial to diagnose arrhythmias. Clinicians can find it challenging to diagnose arrhythmias, and this is a particular issue in more remote and underdeveloped areas. The development of digital ECG and AI methods could assist clinicians who need to diagnose arrhythmias outside of the hospital setting. METHODS: We constructed a large-scale Chinese ECG benchmark dataset using data from 272,753 patients collected from January 2017 to December 2021. The dataset contains ECG recordings from all common arrhythmias present in the Chinese population. Several experienced cardiologists from Shanghai First People's Hospital labeled the dataset. We then developed a deep learning-based multi-label interpretable diagnostic model from the ECG recordings. We utilized Accuracy, F1 score and AUC-ROC to compare the performance of our model with that of the cardiologists, as well as with six comparison models, using testing and hidden data sets. RESULTS: The results show that our approach achieves an F1 score of 83.51%, an average AUC ROC score of 0.977, and 93.74% mean accuracy for 6 common arrhythmias. Results from the hidden dataset demonstrate the performance of our approach exceeds that of cardiologists. Our approach also highlights the diagnostic process. CONCLUSIONS: Our diagnosis system has superior diagnostic performance over that of clinicians. It also has the potential to help clinicians rapidly identify abnormal regions on ECG recordings, thus improving efficiency and accuracy of clinical ECG diagnosis in China. This approach could therefore potentially improve the productivity of out-of-hospital ECG diagnosis and provides a promising prospect for telemedicine.


Arrhythmia, also known as an irregular heartbeat, is a common cardiovascular disease. Sometimes the presence of an arrhythmia can increase the risk of more serious heart conditions. Long-term monitoring of the heartbeat enables arrhythmia to be more easily diagnosed. To accurately detect arrhythmia, we developed a computational model that was able to detect six common types of arrhythmias from readings of the heart rate obtained using a device connected to a mobile phone. We showed that our model could diagnose these arrhythmias in over 270,000 people living in China. Our diagnostic system could enable arrhythmias to be diagnosed more easily outside of hospitals and therefore improve access to healthcare, particularly for those in remote settings.

5.
Front Psychol ; 14: 1110086, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37034913

RESUMO

Education research is increasingly focused on fostering self-regulated learning (SRL) and socially shared regulation of learning (SSRL) among students. However, previous meta-analyses have rarely focused on the specific types of regulated learning scaffolding. Therefore, this meta-analysis examines the effects of different types of regulated learning scaffolding on regulation strategies and academic performance. A total of 46 articles met the inclusion criteria and were included in the final analysis. The findings showed that overall, regulated learning scaffolding had a moderate effect (g = 0.587). In addition, moderation analyses were performed using a random effects model that focused on four types of scaffolding. The results showed that overall, composite tools had the greatest effect, while the most useful scaffolding for SRL and SSRL were group awareness tools (g = 0.61) and composite tools (g = 0.53), respectively. In terms of learning outcomes, composite tools had the greatest effect on regulation strategies, while intelligent pedagogical agents had the greatest effect on academic performance. We also performed a meta-regression analysis to identify the moderators that had the greatest influence on the effects of regulated learning scaffolding. The results showed that grade level, academic subject, and cooperation all had a significant impact. In conclusion, these findings provide evidence for validating the effectiveness of four regulated learning scaffolding and for discovering their function for SSRL, and presented some practical implications of our findings.

7.
J Environ Sci (China) ; 128: 213-223, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36801036

RESUMO

A water-stable bimetallic Fe/Zr metal-organic framework [UiO-66(Fe/Zr)] for exceptional decontamination of arsenic in water was fabricated through a facile one-step strategy. The batch adsorption experiments revealed the excellent performances with ultrafast adsorption kinetics due to the synergistic effects of two functional centers and large surface area (498.33 m2/g). The absorption capacity of UiO-66(Fe/Zr) for arsenate [As(V)] and arsenite [As(III)] reached as high as 204.1 mg/g and 101.7 mg/g, respectively. Langmuir model was suitable to describe the adsorption behaviors of arsenic on UiO-66(Fe/Zr). The fast kinetics (adsorption equilibrium in 30 min, 10 mg/L As) and pseudo-second-order model implied the strong chemisorption between arsenic ions and UiO-66(Fe/Zr), which was further confirmed by DFT theoretical calculations. The results of FT-IR, XPS analysis and TCLP test demonstrated that arsenic was immobilized on the surface of UiO-66(Fe/Zr) through Fe/Zr-O-As bonds, and the leaching rates of the adsorbed As(III) and As(V) from the spent adsorbent were only 5.6% and 1.4%, respectively. UiO-66(Fe/Zr) can be regenerated for five cycles without obvious removal efficiency decrease. The original arsenic (1.0 mg/L) in lake and tap water was effectively removed in 2.0 hr [99.0% of As(III) and 99.8% of As(V)]. The bimetallic UiO-66(Fe/Zr) has great potentials in water deep purification of arsenic with fast kinetics and high capacity.


Assuntos
Arsênio , Poluentes Químicos da Água , Purificação da Água , Arsênio/química , Água , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Purificação da Água/métodos , Adsorção , Poluentes Químicos da Água/química
8.
Psychol Res Behav Manag ; 16: 133-147, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36688227

RESUMO

Purpose: Knowledge-sharing is critical for the survival and development of today's organization, but employees are not always willing to share their knowledge and sometimes even hide it intentionally or unintentionally. Taken from the leadership perspective, this paper aims to investigate the influence of leader hypocrisy on employees' knowledge-hiding behaviors. Drawing on the self-determination theory (SDT), this paper explores the mediating role of basic psychological needs satisfaction, as well as the moderating effect of employees' interdependent self-construal on the relationship between basic psychological needs satisfaction and knowledge-hiding behaviors. The moderated mediation effect is also tested. Methods: The data were collected from companies located in mainland China. The data sample for analysis consists of 336 employees. Hierarchical regression analysis was adopted to test the hypotheses of our proposed model. Results: Leader hypocrisy are positively related to knowledge-hiding behaviors (b = 0.490, p < 0.01). Basic psychological needs satisfaction plays a partial mediating role in such relationship (b =0.118, [0.056, 0.210]). The interdependent self-construal moderates the relationship between basic psychological needs satisfaction and knowledge-hiding behaviors (b = 0.134, p < 0.01), as well as the moderated mediation effect (BootSE = 0.018, [-0.083, -0.009]). Conclusion: The results show that leader hypocrisy is positively related to knowledge-hiding behaviors, and basic psychological needs satisfaction partially mediates such relationship. The interdependent self-construal weakens the negative relationship between basic psychological needs satisfaction and knowledge hiding.

9.
Pharmaceutics ; 16(1)2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38258079

RESUMO

Agglomerate formulations for dry powder inhalation (DPI) formed with fine particles are versatile means for the highly efficient delivery of budesonide. However, uncontrolled agglomeration induces high deposition in the upper airway, causing local side effects due to high mechanical strength, worse deagglomeration, and poor fine-particle delivery. In the present study, fine lactose was mechanically dry-coated prior to particle agglomeration, and the agglomerates were then spheroidized via ultrasonic vibration to improve their aerosol performance. The results showed that the agglomerate produced with the surface-enriched hydrophobic magnesium stearate and ultrasonic vibration demonstrated improved aerosolization properties, benefiting from their lower mechanical strength, less interactive cohesive force, and improved fine powder dispersion behavior. After dispersion utilizing a Turbuhaler® with a pharmaceutical cascade impactor test, a fine particle fraction (FPF) of 71.1 ± 1.3% and an artificial throat deposition of 19.3 ± 0.4% were achieved, suggesting the potential to improve the therapeutic outcomes of budesonide with less localized infections of the mouth and pharynx.

10.
Ecotoxicol Environ Saf ; 245: 114097, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36150305

RESUMO

Binary metallic organic frameworks can always play excellent functions for pollutants removal. One binary MOFs, UiO-66(Fe/Zr)), was newly synthesized and applied to remove aquatic selenite (SeIV) and selenate (SeVI). The adsorption behaviors and mechanisms were investigated using batch experiments, spectroscopic analyses, and theoretical calculations (DFT). The characterization results showed that the material inherited the topological structure of UiO-66 and excellent thermal stability. The large specific surface area (467.52 m2/g) and uniform mesoporous structures of the synthesized MOFs resulted in fast adsorption efficiency and high adsorption capacity for selenium species. The adsorbent kept high adsorption efficiency in a wide pH range from 2 to 11 with good anti-interference ability. The maximum adsorption capacity for Se(IV) and Se(VI) reached as high as 196 mg/g at pH 3 and 258 mg/g at pH 5, respectively. The process was conformed to fit pseudo-second-order kinetics and Langmuir isotherm, and could be explained by the formation of Fe/Zr-O-Se bond on the material surface, which was interpreted by the results of XPS, FTIR and DFT calculation. The regeneration and TCLP experiments demonstrated that UiO-66(Fe/Zr) could be regenerated for five cycles without obvious decrease of efficiencies, and the leaching rate of the adsorbed Se(IV) and Se(VI) in the spent adsorbent were only 4.8% and 2.3%. More than 99% of original Se(IV) and Se(VI) in the lake and tap water samples (1.0 mg/L of Se) could be removed in 2.0 h.


Assuntos
Selênio , Poluentes Químicos da Água , Purificação da Água , Adsorção , Estruturas Metalorgânicas , Ácidos Ftálicos , Ácido Selênico , Ácido Selenioso , Selênio/química , Água/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos
11.
Environ Sci Pollut Res Int ; 29(51): 77131-77144, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35676577

RESUMO

This work aims at exploring a novel environment-friendly nanomaterial based on natural clay minerals for arsenic removal in aqueous samples. Halloysite nanotubes (HNTs) were selected as the substrate with Mn oxides loaded on the surface to enhance its arsenic adsorption ability and then grafted onto the SiO2-coated Fe3O4 microsphere to get a just enough magnetic performance facilitating the material's post-treatment. The prepared composite (Fe3O4@SiO2@Mn-HNTs) was extensively characterized by various instruments including Fourier transform infrared spectroscope (FTIR), scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TG), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscope (XPS), and X-ray diffraction (XRD). Batch experiments were carried out to get the optimum test conditions for arsenic adsorption by the composite, including pH, loading amount of Mn oxides, adsorbent dosage, and the co-existing ions. The adsorption of AsIII and AsV on Fe3O4@SiO2@Mn-HNTs were both well fitted with the pseudo-second-order kinetic model as well as the Langmuir adsorption isotherm model revealing the chemisorption between arsenic and Fe3O4@SiO2@Mn-HNTs. The adsorption process of AsIII and AsV were both endothermic and spontaneous displayed by the thermodynamic study. The capacities of the prepared composite are 3.28 mg g-1 for AsIII and 3.52 mg g-1 for AsV, respectively, which are comparable or better than those of many reported materials in the references. Toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) tests were carried out to access the secondary environmental risk of the composite and showed that it was quite environmentally stable and can be safely disposed. The composite was successfully applied in environmental water samples indicating its great potential applicability in future.


Assuntos
Arsênio , Arsenitos , Nanotubos , Poluentes Químicos da Água , Purificação da Água , Argila , Arseniatos/análise , Arsênio/análise , Arsenitos/análise , Água/análise , Dióxido de Silício , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Óxidos/química , Cinética , Concentração de Íons de Hidrogênio
12.
Front Microbiol ; 13: 845870, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35711760

RESUMO

As one of the common physical remains in archaeological discoveries, human bones are important bases for studying the history of human development, which is of great significance for exploring the evolution law of ancient human, reconstructing ancient human society, and tracking the development of human civilization. However, in the process of human bone burial, in addition to being affected by physical and chemical factors, it will also be affected by microorganisms in the buried soil, resulting in a variety of diseases. According to the determination and analysis of the microbial community structure and diversity in the burial soil of Yangguanzhai Site in Gaoling District in Xi'an city, Shaanxi Province, this paper attempts to explore the influence of microorganisms in the burial environment on human bones, in order to provide scientific proof for the microbial prevention and control of bone relics in the archaeological excavation site. For the first time, Illumina NovaSeq high-throughput sequencing technology was used to analyze the microbial community structure in the burial soil. At the phylum level, there were 8 dominant bacteria species in the soil samples of tombs, which were Firmicutes, Actinobacteriota, Actinobacteria, Proteobacteria, Acidobacteriota, Methylomirabilota, Chloroflexi, Bacteroidota. At the genus level, there were 12 dominant species in the soil samples of tombs, including MIZ17, MND1, Gaiella, oc32, Kroppenstedtia, Halomonas, Bacteroides, Dongia, Faecalibacterium, Nocardioides, Pseudomonas, Pseudonocardia. The overall microorganisms in the soil of Yangguanzhai Cemetery were relatively well-distributed, and the microbial community structure near human bones is the most abundant and diverse. Therefore, it is necessary to take some measures to control microorganisms and protect human bones.

13.
J Exp Bot ; 73(16): 5414-5427, 2022 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-35609084

RESUMO

In Arabidopsis, polarized deposition of wall ingrowths in phloem parenchyma (PP) transfer cells (TCs) occurs adjacent to cells of the sieve element/companion cell (SE/CC) complex. However, the spatial relationships between these different cell types in minor veins, where phloem loading occurs, are poorly understood. PP TC development and wall ingrowth localization were compared with those of other phloem cells in leaves of Col-0 and the transgenic lines AtSUC2::AtSTP9-GFP (green fluorescent protein) and AtSWEET11::AtSWEET11-GFP that identify CCs and PP cells, respectively. The development of PP TCs in minor veins, indicated by deposition of wall ingrowths, proceeded basipetally in leaves. However, not all PP cells develop wall ingrowths, and higher levels of deposition occur in abaxial- compared with adaxial-positioned PP TCs. Furthermore, the deposition of wall ingrowths was exclusively initiated on and preferentially covered the PP TC/SE interface, rather than the PP TC/CC interface, and only occurred in PP cells that were adjacent to SEs. Collectively, these results demonstrate a tight association between SEs and wall ingrowth deposition in PP TCs and suggest the existence of two subtypes of PP cells in leaf minor veins. Compared with PP cells, PP TCs showed more abundant accumulation of AtSWEET11-GFP, indicating functional differences in phloem loading between PP and PP TCs.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Floema/metabolismo , Folhas de Planta/metabolismo
14.
Ecotoxicol Environ Saf ; 228: 112990, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34798359

RESUMO

Metal-organic frameworks (MOFs) have been widely applied for pollutants removal in water. However, the powdered MOFs are always suffered from aggregation during use and difficult collection after use. These problems discount their efficiency and inhibit their reusability. In this work, Zr-based MOF (UiO-66) was successfully imprisoned into a water-stable polyacrylonitrile (PAN) substrate by electrospinning. The containing UiO-66 hybrid membrane was confirmed by instrumental characterizations and its stability was also investigated by ICP-OES analysis. The obtained composite membrane can efficiently remove both arsenite (AsIII) and arsenate (AsV) from water under natural pH conditions. The adsorption kinetic fitted well with pseudo-second-order model and was dominated by chemisorption. Its adsorption isotherm can be described by Langmuir model. The maximal adsorption capacities of the hybrid membrane for As(V) and As(III) were 42.17 mg/g and 32.90 mg/g, respectively. Our results demonstrated that the MOFs-dispersed electrospun nanofiber membrane can greatly inherit the MOFs' original adsorption properties and exhibits good regenerability without loss of MOFs. Electrospinning is an effective and practical method for the preparation of MOFs hybrid membrane, which makes the composite very easy to be collected after use.

15.
Plant Sci ; 310: 110990, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34315604

RESUMO

Transfer cells (TCs) develop extensive wall ingrowths to facilitate enhanced rates of membrane transport. In Arabidopsis, TCs trans-differentiate from phloem parenchyma (PP) cells abutting the sieve element/companion cell complex in minor veins of foliar tissues and, based on anatomy and expression of SWEET sucrose uniporters, are assumed to play pivotal roles in phloem loading. While wall ingrowth deposition in PP TCs is a dynamic process responding to abiotic stresses such as high light and cold, the transcriptional control of PP TC development, including deposition of the wall ingrowths themselves, is not understood. PP TC development is a trait of vegetative phase change, potentially linking wall ingrowth deposition with floral induction. Transcript profiling by RNA-seq identified NAC056 and NAC018 (NARS1 and NARS2) as putative regulators of wall ingrowth deposition, while recent single cell RNA-seq analysis of leaf vasculature identified PP-specific expression of NAC056. Numerous membrane transporters, particularly of the UmamiT family of amino acid efflux carriers, were also identified. Collectively, these findings, and the recent discovery that wall ingrowth deposition is regulated by sucrose-dependent loading activity of these cells, provide new insights into the biology of PP TCs and their importance to phloem loading in Arabidopsis, establishing these cells as a key transport hub for phloem loading.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Floema/metabolismo , Proteínas de Arabidopsis/genética , Parede Celular/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Folhas de Planta/metabolismo , Análise de Sequência de RNA/métodos
17.
Plant Cell Physiol ; 61(10): 1775-1787, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32761075

RESUMO

To understand plant growth and development, it is often necessary to investigate the organization of plant cells and plant cell walls. Plant cell walls are often fluorescently labeled for confocal imaging with the dye propidium iodide using a pseudo-Schiff reaction. This reaction binds free amine groups on dye molecules to aldehyde groups on cellulose that result from oxidation with periodic acid. We tested a range of fluorescent dyes carrying free amine groups for their ability to act as pseudo-Schiff reagents. Using the low-pH solution historically used for the Schiff reaction, these alternative dyes failed to label cell walls of Arabidopsis cotyledon vascular tissue as strongly as propidium iodide but replacing the acidic solution with water greatly improved fluorescence labeling. Under these conditions, rhodamine-123 provided improved staining of plant cell walls compared to propidium iodide. We also developed protocols for pseudo-Schiff labeling with ATTO 647N-amine, a dye compatible for super-resolution Stimulated Emission Depletion (STED) imaging. ATTO 647N-amine was used for super-resolution imaging of cell wall ingrowths that occur in phloem parenchyma transfer cells of Arabidopsis, structures whose small size is only slightly larger than the resolution limit of conventional confocal microscopy. Application of surface-rendering software demonstrated the increase in plasma membrane surface area as a consequence of wall ingrowth deposition and suggests that STED-based approaches will be useful for more detailed morphological analysis of wall ingrowth formation. These improvements in pseudo-Schiff labeling for conventional confocal microscopy and STED imaging will be broadly applicable for high-resolution imaging of plant cell walls.


Assuntos
Arabidopsis/ultraestrutura , Parede Celular/ultraestrutura , Corantes Fluorescentes , Imagem Óptica/métodos , Arabidopsis/crescimento & desenvolvimento , Membrana Celular/ultraestrutura , Celulose/metabolismo , Microscopia Confocal , Propídio , Rodamina 123
18.
J Exp Bot ; 71(16): 4690-4702, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32433727

RESUMO

In Arabidopsis thaliana, phloem parenchyma transfer cells (PPTCs) occur in leaf minor veins and play a pivotal role in phloem loading. Wall ingrowth formation in PPTCs is induced by the phloem loading activity of these cells, which is regulated by sucrose (Suc). The effects of endogenous versus exogenous Suc on wall ingrowth deposition, however, differ. Elevating endogenous Suc levels by increased light enhanced wall ingrowth formation, whereas lowering endogenous Suc levels by dark treatment or genetically in ch-1 resulted in lower levels of deposition. In contrast, exogenously applied Suc, or Suc derived from other organs, repressed wall ingrowth deposition. Analysis of pAtSUC2::GFP plants, used as a marker for phloem loading status, suggested that wall ingrowth formation is correlated with phloem loading activity. Gene expression analysis revealed that exogenous Suc down-regulated expression of AtSWEET11 and 12, whereas endogenous Suc up-regulated AtSWEET11 expression. Analysis of a TREHALOSE 6-PHOSPHATE (T6P) SYNTHASE overexpression line and the hexokinase (HXK)-null mutant, gin2-1, suggested that Suc signalling of wall ingrowth formation is independent of T6P and HXK. Collectively, these results are consistent with the conclusion that Suc regulates wall ingrowth formation via affecting Suc exporting activity in PPTCs.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Floema/metabolismo , Folhas de Planta/metabolismo , Sacarose
19.
Eur J Med Chem ; 183: 111650, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31539780

RESUMO

Inspired by the traditional Chinese herbal pair of Polygala tenuifolia-Acori Tatarinowii for treating epilepsy, 33 novel substituted cinnamic α-asaronol esters and analogues were designed by Combination of Traditional Chinese Medicine Molecular Chemistry (CTCMMC) strategy, synthesized and tested systematically not only for anticonvulsant activity in three mouse models but also for LDH inhibitory activity. Thereinto, 68-70 and 75 displayed excellent and broad spectra of anticonvulsant activities with modest ability in preventing neuropathic pain, as well as low neurotoxicity. The protective indices of these four compounds compared favorably with stiripentol, lacosamide, carbamazepine and valproic acid. 68-70 exhibited good LDH1 and LDH5 inhibitory activities with noncompetitive inhibition type, and were more potent than stiripentol. Notably, 70, as a representative agent, was also shown as a moderately positive allosteric modulator at human α1ß2γ2 GABAA receptors (EC50 46.3 ±â€¯7.3 µM). Thus, 68-70 were promising candidates for developing into anti-epileptic drugs, especially for treatment of refractory epilepsies such as Dravet syndrome.


Assuntos
Anisóis/química , Anticonvulsivantes/química , Cinamatos/química , Medicamentos de Ervas Chinesas/química , Ésteres/química , L-Lactato Desidrogenase/antagonistas & inibidores , Polygala/química , Regulação Alostérica , Animais , Anisóis/farmacologia , Anticonvulsivantes/farmacologia , Carbamazepina/química , Carbamazepina/farmacologia , Cinamatos/farmacologia , Dioxolanos/química , Dioxolanos/farmacologia , Desenho de Fármacos , Medicamentos de Ervas Chinesas/farmacologia , Ésteres/farmacologia , Humanos , Medicina Tradicional Chinesa , Camundongos , Estrutura Molecular , Neuralgia/prevenção & controle , Receptores de GABA-A/metabolismo , Relação Estrutura-Atividade , Ácido Valproico/química , Ácido Valproico/farmacologia
20.
Pharmacol Rep ; 70(1): 69-74, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29331789

RESUMO

BACKGROUND: Epilepsy is one of chronic neurological disorders that affects 0.5-1.0% of the world's population during their lifetime. There is a still significant need to develop novel anticonvulsant drugs that possess superior efficacy, broad spectrum of activities and good safety profile. METHODS: α-Asaronol and two current antiseizure drugs (α-asarone and carbamazepine (CBZ)) were assessed by in vivo anticonvulsant screening with the three most employed standard animal seizure models, including maximal electroshock seizure (MES), subcutaneous injection-pentylenetetrazole (PTZ)-induced seizures and 3-mercaptopropionic acid (3-MP)-induced seizures in mice. Considering drug safety evaluation, acute neurotoxicity was assessed with minimal motor impairment screening determined in the rotarod test, and acute toxicity was also detected in mice. RESULTS: In our results, α-asaronol displayed a broad spectrum of anticonvulsant activity (ACA) and showed better protective indexes (PI = 11.11 in MES, PI = 8.68 in PTZ) and lower acute toxicity (LD50 = 2940 mg/kg) than its metabolic parent compound (α-asarone). Additionally, α-asaronol displayed a prominent anticonvulsant profile with ED50 values of 62.02 mg/kg in the MES and 79.45 mg/kg in the sc-PTZ screen as compared with stiripentol of ED50 of 240 mg/kg and 115 mg/kg in the relevant test, respectively. CONCLUSION: The results of the present study revealed α-asaronol can be developed as a novel molecular in the search for safer and efficient anticonvulsants having neuroprotective effects as well as low toxicity. Meanwhile, the results also suggested that α-asaronol has great potential to develop into another new aromatic allylic alcohols type anticonvulsant drug for add-on therapy of Dravet's syndrome.


Assuntos
Anisóis/farmacologia , Anticonvulsivantes/farmacologia , Encéfalo/efeitos dos fármacos , Convulsões/prevenção & controle , Ácido 3-Mercaptopropiônico , Derivados de Alilbenzenos , Animais , Anisóis/toxicidade , Anticonvulsivantes/toxicidade , Encéfalo/fisiopatologia , Dioxolanos/farmacologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Eletrochoque , Dose Letal Mediana , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/fisiopatologia , Pentilenotetrazol , Teste de Desempenho do Rota-Rod , Convulsões/induzido quimicamente , Convulsões/fisiopatologia
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